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   1 /*
   2  * linux/drivers/s390/scsi/zfcp_qdio.c
   3  *
   4  * FCP adapter driver for IBM eServer zSeries
   5  *
   6  * QDIO related routines
   7  *
   8  * (C) Copyright IBM Corp. 2002, 2004
   9  *
  10  * Authors:
  11  *      Martin Peschke <mpeschke@de.ibm.com>
  12  *      Raimund Schroeder <raimund.schroeder@de.ibm.com>
  13  *      Wolfgang Taphorn
  14  *      Heiko Carstens <heiko.carstens@de.ibm.com>
  15  *      Andreas Herrmann <aherrman@de.ibm.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2, or (at your option)
  20  * any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  */
  31
  32 #include "zfcp_ext.h"
  33
  34 static inline void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
  35 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
  36         (struct zfcp_qdio_queue *, int, int);
  37 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
  38         (struct zfcp_fsf_req *, int, int);
  39 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
  40         (struct zfcp_fsf_req *, unsigned long);
  41 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
  42         (struct zfcp_fsf_req *, unsigned long);
  43 static inline int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
  44 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
  45 static inline void zfcp_qdio_sbale_fill
  46         (struct zfcp_fsf_req *, unsigned long, void *, int);
  47 static inline int zfcp_qdio_sbals_from_segment
  48         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
  49 static inline int zfcp_qdio_sbals_from_buffer
  50         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
  51
  52 static qdio_handler_t zfcp_qdio_request_handler;
  53 static qdio_handler_t zfcp_qdio_response_handler;
  54 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
  55         unsigned int, unsigned int, unsigned int, int, int);
  56
  57 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
  58
  59 /*
  60  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
  61  * array in the adapter struct.
  62  * Cur_buf is the pointer array and count can be any number of required
  63  * buffers, the page-fitting arithmetic is done entirely within this funciton.
  64  *
  65  * returns:     number of buffers allocated
  66  * locks:       must only be called with zfcp_data.config_sema taken
  67  */
  68 static int
  69 zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
  70 {
  71         int buf_pos;
  72         int qdio_buffers_per_page;
  73         int page_pos = 0;
  74         struct qdio_buffer *first_in_page = NULL;
  75
  76         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
  77         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
  78
  79         for (buf_pos = 0; buf_pos < count; buf_pos++) {
  80                 if (page_pos == 0) {
  81                         cur_buf[buf_pos] = (struct qdio_buffer *)
  82                             get_zeroed_page(GFP_KERNEL);
  83                         if (cur_buf[buf_pos] == NULL) {
  84                                 ZFCP_LOG_INFO("error: allocation of "
  85                                               "QDIO buffer failed \n");
  86                                 goto out;
  87                         }
  88                         first_in_page = cur_buf[buf_pos];
  89                 } else {
  90                         cur_buf[buf_pos] = first_in_page + page_pos;
  91
  92                 }
  93                 /* was initialised to zero */
  94                 page_pos++;
  95                 page_pos %= qdio_buffers_per_page;
  96         }
  97  out:
  98         return buf_pos;
  99 }
 100
 101 /*
 102  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
 103  * in the adapter struct cur_buf is the pointer array and count can be any
 104  * number of buffers in the array that should be freed starting from buffer 0
 105  *
 106  * locks:       must only be called with zfcp_data.config_sema taken
 107  */
 108 static void
 109 zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
 110 {
 111         int buf_pos;
 112         int qdio_buffers_per_page;
 113
 114         qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
 115         ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
 116
 117         for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
 118                 free_page((unsigned long) cur_buf[buf_pos]);
 119         return;
 120 }
 121
 122 /* locks:       must only be called with zfcp_data.config_sema taken */
 123 int
 124 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
 125 {
 126         int buffer_count;
 127         int retval = 0;
 128
 129         buffer_count =
 130             zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
 131                                       QDIO_MAX_BUFFERS_PER_Q);
 132         if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
 133                 ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
 134                                "queue\n", buffer_count);
 135                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 136                                           buffer_count);
 137                 retval = -ENOMEM;
 138                 goto out;
 139         }
 140
 141         buffer_count =
 142             zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
 143                                       QDIO_MAX_BUFFERS_PER_Q);
 144         if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
 145                 ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
 146                                "queue", buffer_count);
 147                 zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 148                                           buffer_count);
 149                 ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 150                 zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 151                                           QDIO_MAX_BUFFERS_PER_Q);
 152                 retval = -ENOMEM;
 153                 goto out;
 154         }
 155  out:
 156         return retval;
 157 }
 158
 159 /* locks:       must only be called with zfcp_data.config_sema taken */
 160 void
 161 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
 162 {
 163         ZFCP_LOG_TRACE("freeing request_queue buffers\n");
 164         zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
 165                                   QDIO_MAX_BUFFERS_PER_Q);
 166
 167         ZFCP_LOG_TRACE("freeing response_queue buffers\n");
 168         zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
 169                                   QDIO_MAX_BUFFERS_PER_Q);
 170 }
 171
 172 int
 173 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
 174 {
 175         struct qdio_initialize *init_data;
 176
 177         init_data = &adapter->qdio_init_data;
 178
 179         init_data->cdev = adapter->ccw_device;
 180         init_data->q_format = QDIO_SCSI_QFMT;
 181         memcpy(init_data->adapter_name, &adapter->name, 8);
 182         init_data->qib_param_field_format = 0;
 183         init_data->qib_param_field = NULL;
 184         init_data->input_slib_elements = NULL;
 185         init_data->output_slib_elements = NULL;
 186         init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
 187         init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
 188         init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
 189         init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
 190         init_data->no_input_qs = 1;
 191         init_data->no_output_qs = 1;
 192         init_data->input_handler = zfcp_qdio_response_handler;
 193         init_data->output_handler = zfcp_qdio_request_handler;
 194         init_data->int_parm = (unsigned long) adapter;
 195         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
 196             QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
 197         init_data->input_sbal_addr_array =
 198             (void **) (adapter->response_queue.buffer);
 199         init_data->output_sbal_addr_array =
 200             (void **) (adapter->request_queue.buffer);
 201
 202         return qdio_allocate(init_data);
 203 }
 204
 205 /*
 206  * function:    zfcp_qdio_handler_error_check
 207  *
 208  * purpose:     called by the response handler to determine error condition
 209  *
 210  * returns:     error flag
 211  *
 212  */
 213 static inline int
 214 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
 215                               unsigned int qdio_error, unsigned int siga_error,
 216                               int first_element, int elements_processed)
 217 {
 218         int retval = 0;
 219
 220         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
 221                 retval = -EIO;
 222
 223                 ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
 224                               "qdio_error=0x%x, siga_error=0x%x)\n",
 225                               status, qdio_error, siga_error);
 226
 227                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
 228                                 first_element, elements_processed);
 229                /*
 230                 * Restarting IO on the failed adapter from scratch.
 231                 * Since we have been using this adapter, it is save to assume
 232                 * that it is not failed but recoverable. The card seems to
 233                 * report link-up events by self-initiated queue shutdown.
 234                 * That is why we need to clear the the link-down flag
 235                 * which is set again in case we have missed by a mile.
 236                 */
 237                zfcp_erp_adapter_reopen(
 238                        adapter,
 239                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
 240                        ZFCP_STATUS_COMMON_ERP_FAILED);
 241         }
 242         return retval;
 243 }
 244
 245 /*
 246  * function:    zfcp_qdio_request_handler
 247  *
 248  * purpose:     is called by QDIO layer for completed SBALs in request queue
 249  *
 250  * returns:     (void)
 251  */
 252 static void
 253 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
 254                           unsigned int status,
 255                           unsigned int qdio_error,
 256                           unsigned int siga_error,
 257                           unsigned int queue_number,
 258                           int first_element,
 259                           int elements_processed,
 260                           unsigned long int_parm)
 261 {
 262         struct zfcp_adapter *adapter;
 263         struct zfcp_qdio_queue *queue;
 264
 265         adapter = (struct zfcp_adapter *) int_parm;
 266         queue = &adapter->request_queue;
 267
 268         ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
 269                        zfcp_get_busid_by_adapter(adapter),
 270                        first_element, elements_processed);
 271
 272         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 273                                                    siga_error, first_element,
 274                                                    elements_processed)))
 275                 goto out;
 276         /*
 277          * we stored address of struct zfcp_adapter  data structure
 278          * associated with irq in int_parm
 279          */
 280
 281         /* cleanup all SBALs being program-owned now */
 282         zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
 283
 284         /* increase free space in outbound queue */
 285         atomic_add(elements_processed, &queue->free_count);
 286         ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
 287         wake_up(&adapter->request_wq);
 288         ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
 289                        elements_processed, atomic_read(&queue->free_count));
 290  out:
 291         return;
 292 }
 293
 294 /*
 295  * function:    zfcp_qdio_response_handler
 296  *
 297  * purpose:     is called by QDIO layer for completed SBALs in response queue
 298  *
 299  * returns:     (void)
 300  */
 301 static void
 302 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
 303                            unsigned int status,
 304                            unsigned int qdio_error,
 305                            unsigned int siga_error,
 306                            unsigned int queue_number,
 307                            int first_element,
 308                            int elements_processed,
 309                            unsigned long int_parm)
 310 {
 311         struct zfcp_adapter *adapter;
 312         struct zfcp_qdio_queue *queue;
 313         int buffer_index;
 314         int i;
 315         struct qdio_buffer *buffer;
 316         int retval = 0;
 317         u8 count;
 318         u8 start;
 319         volatile struct qdio_buffer_element *buffere = NULL;
 320         int buffere_index;
 321
 322         adapter = (struct zfcp_adapter *) int_parm;
 323         queue = &adapter->response_queue;
 324
 325         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
 326                                                    siga_error, first_element,
 327                                                    elements_processed)))
 328                 goto out;
 329
 330         /*
 331          * we stored address of struct zfcp_adapter  data structure
 332          * associated with irq in int_parm
 333          */
 334
 335         buffere = &(queue->buffer[first_element]->element[0]);
 336         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
 337         /*
 338          * go through all SBALs from input queue currently
 339          * returned by QDIO layer
 340          */
 341
 342         for (i = 0; i < elements_processed; i++) {
 343
 344                 buffer_index = first_element + i;
 345                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
 346                 buffer = queue->buffer[buffer_index];
 347
 348                 /* go through all SBALEs of SBAL */
 349                 for (buffere_index = 0;
 350                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
 351                      buffere_index++) {
 352
 353                         /* look for QDIO request identifiers in SB */
 354                         buffere = &buffer->element[buffere_index];
 355                         retval = zfcp_qdio_reqid_check(adapter,
 356                                                        (void *) buffere->addr);
 357
 358                         if (retval) {
 359                                 ZFCP_LOG_NORMAL("bug: unexpected inbound "
 360                                                 "packet on adapter %s "
 361                                                 "(reqid=0x%lx, "
 362                                                 "first_element=%d, "
 363                                                 "elements_processed=%d)\n",
 364                                                 zfcp_get_busid_by_adapter(adapter),
 365                                                 (unsigned long) buffere->addr,
 366                                                 first_element,
 367                                                 elements_processed);
 368                                 ZFCP_LOG_NORMAL("hex dump of inbound buffer "
 369                                                 "at address %p "
 370                                                 "(buffer_index=%d, "
 371                                                 "buffere_index=%d)\n", buffer,
 372                                                 buffer_index, buffere_index);
 373                                 ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
 374                                               (char *) buffer, SBAL_SIZE);
 375                         }
 376                         /*
 377                          * A single used SBALE per inbound SBALE has been
 378                          * implemented by QDIO so far. Hope they will
 379                          * do some optimisation. Will need to change to
 380                          * unlikely() then.
 381                          */
 382                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
 383                                 break;
 384                 };
 385
 386                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
 387                         ZFCP_LOG_NORMAL("bug: End of inbound data "
 388                                         "not marked!\n");
 389                 }
 390         }
 391
 392         /*
 393          * put range of SBALs back to response queue
 394          * (including SBALs which have already been free before)
 395          */
 396         count = atomic_read(&queue->free_count) + elements_processed;
 397         start = queue->free_index;
 398
 399         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
 400                        "queue_no=%i, index_in_queue=%i, count=%i, "
 401                        "buffers=0x%lx\n",
 402                        zfcp_get_busid_by_adapter(adapter),
 403                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 404                        0, start, count, (unsigned long) &queue->buffer[start]);
 405
 406         retval = do_QDIO(ccw_device,
 407                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
 408                          0, start, count, NULL);
 409
 410         if (unlikely(retval)) {
 411                 atomic_set(&queue->free_count, count);
 412                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
 413                                "queues may be down "
 414                                "(count=%d, start=%d, retval=%d)\n",
 415                                count, start, retval);
 416         } else {
 417                 queue->free_index += count;
 418                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
 419                 atomic_set(&queue->free_count, 0);
 420                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
 421                                "queue at position %i\n", count, start);
 422         }
 423  out:
 424         return;
 425 }
 426
 427 /*
 428  * function:    zfcp_qdio_reqid_check
 429  *
 430  * purpose:     checks for valid reqids or unsolicited status
 431  *
 432  * returns:     0 - valid request id or unsolicited status
 433  *              !0 - otherwise
 434  */
 435 int
 436 zfcp_qdio_reqid_check(struct zfcp_adapter *adapter, void *sbale_addr)
 437 {
 438         struct zfcp_fsf_req *fsf_req;
 439
 440         /* invalid (per convention used in this driver) */
 441         if (unlikely(!sbale_addr)) {
 442                 ZFCP_LOG_NORMAL("bug: invalid reqid\n");
 443                 return -EINVAL;
 444         }
 445
 446         /* valid request id and thus (hopefully :) valid fsf_req address */
 447         fsf_req = (struct zfcp_fsf_req *) sbale_addr;
 448
 449         /* serialize with zfcp_fsf_req_dismiss_all */
 450         spin_lock(&adapter->fsf_req_list_lock);
 451         if (list_empty(&adapter->fsf_req_list_head)) {
 452                 spin_unlock(&adapter->fsf_req_list_lock);
 453                 return 0;
 454         }
 455         list_del(&fsf_req->list);
 456         atomic_dec(&adapter->fsf_reqs_active);
 457         spin_unlock(&adapter->fsf_req_list_lock);
 458
 459         if (unlikely(adapter != fsf_req->adapter)) {
 460                 ZFCP_LOG_NORMAL("bug: invalid reqid (fsf_req=%p, "
 461                                 "fsf_req->adapter=%p, adapter=%p)\n",
 462                                 fsf_req, fsf_req->adapter, adapter);
 463                 return -EINVAL;
 464         }
 465
 466         /* finish the FSF request */
 467         zfcp_fsf_req_complete(fsf_req);
 468
 469         return 0;
 470 }
 471
 472 /**
 473  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
 474  * @queue: queue from which SBALE should be returned
 475  * @sbal: specifies number of SBAL in queue
 476  * @sbale: specifes number of SBALE in SBAL
 477  */
 478 static inline volatile struct qdio_buffer_element *
 479 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
 480 {
 481         return &queue->buffer[sbal]->element[sbale];
 482 }
 483
 484 /**
 485  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
 486  *      a struct zfcp_fsf_req
 487  */
 488 inline volatile struct qdio_buffer_element *
 489 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 490 {
 491         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
 492                                    sbal, sbale);
 493 }
 494
 495 /**
 496  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
 497  *      a struct zfcp_fsf_req
 498  */
 499 static inline volatile struct qdio_buffer_element *
 500 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
 501 {
 502         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
 503                                    sbal, sbale);
 504 }
 505
 506 /**
 507  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
 508  *      a struct zfcp_fsf_req
 509  */
 510 inline volatile struct qdio_buffer_element *
 511 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
 512 {
 513         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
 514                                    fsf_req->sbale_curr);
 515 }
 516
 517 /**
 518  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
 519  *      on the request_queue for a struct zfcp_fsf_req
 520  * @fsf_req: the number of the last SBAL that can be used is stored herein
 521  * @max_sbals: used to pass an upper limit for the number of SBALs
 522  *
 523  * Note: We can assume at least one free SBAL in the request_queue when called.
 524  */
 525 static inline void
 526 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
 527 {
 528         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
 529         count = min(count, max_sbals);
 530         fsf_req->sbal_last  = fsf_req->sbal_first;
 531         fsf_req->sbal_last += (count - 1);
 532         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
 533 }
 534
 535 /**
 536  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
 537  *      request
 538  * @fsf_req: zfcp_fsf_req to be processed
 539  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
 540  *
 541  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
 542  */
 543 static inline volatile struct qdio_buffer_element *
 544 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 545 {
 546         volatile struct qdio_buffer_element *sbale;
 547
 548         /* set last entry flag in current SBALE of current SBAL */
 549         sbale = zfcp_qdio_sbale_curr(fsf_req);
 550         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 551
 552         /* don't exceed last allowed SBAL */
 553         if (fsf_req->sbal_curr == fsf_req->sbal_last)
 554                 return NULL;
 555
 556         /* set chaining flag in first SBALE of current SBAL */
 557         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 558         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
 559
 560         /* calculate index of next SBAL */
 561         fsf_req->sbal_curr++;
 562         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
 563
 564         /* keep this requests number of SBALs up-to-date */
 565         fsf_req->sbal_number++;
 566
 567         /* start at first SBALE of new SBAL */
 568         fsf_req->sbale_curr = 0;
 569
 570         /* set storage-block type for new SBAL */
 571         sbale = zfcp_qdio_sbale_curr(fsf_req);
 572         sbale->flags |= sbtype;
 573
 574         return sbale;
 575 }
 576
 577 /**
 578  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
 579  */
 580 static inline volatile struct qdio_buffer_element *
 581 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
 582 {
 583         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
 584                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
 585
 586         fsf_req->sbale_curr++;
 587
 588         return zfcp_qdio_sbale_curr(fsf_req);
 589 }
 590
 591 /**
 592  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
 593  *      with zero from
 594  */
 595 static inline int
 596 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
 597 {
 598         struct qdio_buffer **buf = queue->buffer;
 599         int curr = first;
 600         int count = 0;
 601
 602         for(;;) {
 603                 curr %= QDIO_MAX_BUFFERS_PER_Q;
 604                 count++;
 605                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
 606                 if (curr == last)
 607                         break;
 608                 curr++;
 609         }
 610         return count;
 611 }
 612
 613
 614 /**
 615  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
 616  */
 617 static inline int
 618 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
 619 {
 620         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
 621                                     fsf_req->sbal_first, fsf_req->sbal_curr);
 622 }
 623
 624
 625 /**
 626  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
 627  *      on request_queue
 628  */
 629 static inline void
 630 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 631                      void *addr, int length)
 632 {
 633         volatile struct qdio_buffer_element *sbale;
 634
 635         sbale = zfcp_qdio_sbale_curr(fsf_req);
 636         sbale->addr = addr;
 637         sbale->length = length;
 638 }
 639
 640 /**
 641  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
 642  * @fsf_req: request to be processed
 643  * @sbtype: SBALE flags
 644  * @start_addr: address of memory segment
 645  * @total_length: length of memory segment
 646  *
 647  * Alignment and length of the segment determine how many SBALEs are needed
 648  * for the memory segment.
 649  */
 650 static inline int
 651 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 652                              void *start_addr, unsigned long total_length)
 653 {
 654         unsigned long remaining, length;
 655         void *addr;
 656
 657         /* split segment up heeding page boundaries */
 658         for (addr = start_addr, remaining = total_length; remaining > 0;
 659              addr += length, remaining -= length) {
 660                 /* get next free SBALE for new piece */
 661                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
 662                         /* no SBALE left, clean up and leave */
 663                         zfcp_qdio_sbals_wipe(fsf_req);
 664                         return -EINVAL;
 665                 }
 666                 /* calculate length of new piece */
 667                 length = min(remaining,
 668                              (PAGE_SIZE - ((unsigned long) addr &
 669                                            (PAGE_SIZE - 1))));
 670                 /* fill current SBALE with calculated piece */
 671                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
 672         }
 673         return total_length;
 674 }
 675
 676
 677 /**
 678  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 679  * @fsf_req: request to be processed
 680  * @sbtype: SBALE flags
 681  * @sg: scatter-gather list
 682  * @sg_count: number of elements in scatter-gather list
 683  * @max_sbals: upper bound for number of SBALs to be used
 684  */
 685 inline int
 686 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 687                         struct scatterlist *sg, int sg_count, int max_sbals)
 688 {
 689         int sg_index;
 690         struct scatterlist *sg_segment;
 691         int retval;
 692         volatile struct qdio_buffer_element *sbale;
 693         int bytes = 0;
 694
 695         /* figure out last allowed SBAL */
 696         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
 697
 698         /* set storage-block type for current SBAL */
 699         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 700         sbale->flags |= sbtype;
 701
 702         /* process all segements of scatter-gather list */
 703         for (sg_index = 0, sg_segment = sg, bytes = 0;
 704              sg_index < sg_count;
 705              sg_index++, sg_segment++) {
 706                 retval = zfcp_qdio_sbals_from_segment(
 707                                 fsf_req,
 708                                 sbtype,
 709                                 zfcp_sg_to_address(sg_segment),
 710                                 sg_segment->length);
 711                 if (retval < 0) {
 712                         bytes = retval;
 713                         goto out;
 714                 } else
 715                         bytes += retval;
 716         }
 717         /* assume that no other SBALEs are to follow in the same SBAL */
 718         sbale = zfcp_qdio_sbale_curr(fsf_req);
 719         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
 720 out:
 721         return bytes;
 722 }
 723
 724
 725 /**
 726  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
 727  * @fsf_req: request to be processed
 728  * @sbtype: SBALE flags
 729  * @buffer: data buffer
 730  * @length: length of buffer
 731  * @max_sbals: upper bound for number of SBALs to be used
 732  */
 733 static inline int
 734 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
 735                             void *buffer, unsigned long length, int max_sbals)
 736 {
 737         struct scatterlist sg_segment;
 738
 739         zfcp_address_to_sg(buffer, &sg_segment);
 740         sg_segment.length = length;
 741
 742         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
 743                                        max_sbals);
 744 }
 745
 746
 747 /**
 748  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
 749  * @fsf_req: request to be processed
 750  * @sbtype: SBALE flags
 751  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
 752  *      to fill SBALs
 753  */
 754 inline int
 755 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
 756                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
 757 {
 758         if (scsi_cmnd->use_sg) {
 759                 return zfcp_qdio_sbals_from_sg(fsf_req, sbtype,
 760                                                (struct scatterlist *)
 761                                                scsi_cmnd->request_buffer,
 762                                                scsi_cmnd->use_sg,
 763                                                ZFCP_MAX_SBALS_PER_REQ);
 764         } else {
 765                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
 766                                                    scsi_cmnd->request_buffer,
 767                                                    scsi_cmnd->request_bufflen,
 768                                                    ZFCP_MAX_SBALS_PER_REQ);
 769         }
 770 }
 771
 772 /**
 773  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
 774  */
 775 int
 776 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
 777                         struct zfcp_fsf_req *fsf_req)
 778 {
 779         int new_distance_from_int;
 780         int pci_pos;
 781         volatile struct qdio_buffer_element *sbale;
 782
 783         new_distance_from_int = req_queue->distance_from_int +
 784                 fsf_req->sbal_number;
 785
 786         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
 787                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
 788                 pci_pos  = fsf_req->sbal_first;
 789                 pci_pos += fsf_req->sbal_number;
 790                 pci_pos -= new_distance_from_int;
 791                 pci_pos -= 1;
 792                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
 793                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
 794                 sbale->flags |= SBAL_FLAGS0_PCI;
 795         }
 796         return new_distance_from_int;
 797 }
 798
 799 /*
 800  * function:    zfcp_zero_sbals
 801  *
 802  * purpose:     zeros specified range of SBALs
 803  *
 804  * returns:
 805  */
 806 void
 807 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
 808 {
 809         int cur_pos;
 810         int index;
 811
 812         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
 813                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
 814                 memset(buf[index], 0, sizeof (struct qdio_buffer));
 815                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
 816                                index, buf[index]);
 817         }
 818 }
 819
 820 #undef ZFCP_LOG_AREA